A three-modality coaxial integrated catheter structure for imaging of a body lumen

Abstract

This invention proposes a trimodal coaxial integrated catheter structure for in vivo cavity imaging. The trimodal coaxial integrated catheter structure for in vivo cavity imaging includes a flexible main body segment and a front imaging working segment. The front imaging working segment includes a metal protective shell and a broadband freeform surface focusing micro-optical device and an ultrasonic transducer module disposed inside the metal protective shell. The broadband freeform surface focusing micro-optical device has a reflective surface, which substantially overlaps the optical focusing areas of the OCT near-infrared beam and the FLIM excitation beam, and overlaps with the IVUS main acoustic beam imaging area or scanning section of the ultrasonic transducer module in the same axial position and circumferential direction. The flexible main body segment is used to transmit rotational torque during rotational scanning. The flexible main body segment is connected to the front imaging working segment. This invention utilizes the broadband freeform surface focusing micro-optical device for reflective focusing, enabling high-resolution trimodal imaging.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a trimodal coaxial integrated catheter structure for in vivo cavity imaging. Background Technology

[0002] Existing intracavitary multimodal imaging technologies have inherent limitations. For example, the commercially available IVUS-OCT dual-modal solution can only achieve structural imaging, completely lacking FLIM biochemical functional diagnostic information, resulting in a blind spot in clinical diagnosis. Furthermore, its optical architecture based on GRIN lenses and reflecting prisms is only compatible with the OCT near-infrared band and cannot be compatible with the transmission and focusing of FLIM ultraviolet light, lacking trimodal extension capabilities. Existing OCT-FLIM dual-optical modal solutions are limited by the short optical imaging penetration depth, unable to obtain full-layer structural information of the cavity wall, thus limiting clinical applications. The traditional optical components used, such as fused silica spherical lenses and GRIN lenses, have inherent chromatic aberration and spherical aberration, resulting in a severe mismatch between the effective working distance of OCT and FLIM across a wide dual-wavelength range. This makes it impossible to simultaneously achieve high-resolution focusing and efficient fluorescence collection. The optical system of these components occupies a large space, making it difficult to integrate with ultrasound modules and failing to meet the outer diameter constraints of clinical intervention. Existing multimodal imaging either suffers from poor compatibility or has problems with single imaging or poor resolution.

[0003] To address the inherent limitations of existing multimodal intravascular imaging technologies, three core technological bottlenecks need to be overcome: firstly, the need to integrate intravascular ultrasound (IVUS), optical coherence tomography (OCT), and fluorescence lifetime imaging technologies within the constraints of millimeter-level outer diameters suitable for clinical intervention; and secondly, the need to overcome these bottlenecks. There are three main challenges in achieving compact, coaxial spatial integration of three imaging units (OCT, FLIM, and OCT) based on different physical mechanisms. First, the non-collinear component arrangement commonly used in existing multimodal catheters results in spatial offset of the imaging area and time difference in signal acquisition, leading to insufficient registration accuracy of multimodal images and making it difficult to provide clinicians with highly reliable diagnostic data that corresponds one-to-one with macroscopic tissue structure, microscopic fine structure, and tissue biochemical characteristics. Second, there is a significant wavelength difference between the near-infrared light used in OCT and the ultraviolet light used in FLIM. Existing conventional spherical and aspherical optical devices cannot simultaneously achieve high-resolution focusing and efficient fluorescence signal collection in both wavelength bands. There is an inherent contradiction that the imaging performance of one modality must be sacrificed to adapt to a single wavelength. Furthermore, the combination scheme of multiple optical elements will further compress the already limited assembly space within the catheter, exacerbating the design difficulty of miniaturization integration. These three factors make it difficult to achieve compact, coaxial spatial integration.

[0004] In view of this, the present invention provides a trimodal coaxial integrated catheter structure for in vivo cavity imaging. Summary of the Invention

[0005] To address the challenge of integrating multiple imaging structures in existing technologies, this invention proposes a trimodal coaxial integrated catheter structure for in vivo cavity imaging.

[0006] This invention is achieved through the following technical solution: This invention proposes a trimodal coaxial integrated catheter structure for in vivo cavity imaging, comprising a flexible main body segment and a front imaging working segment, wherein: The front-end imaging section includes a metal protective shell and a broadband freeform surface focusing micro-optical device and an ultrasonic transducer module disposed inside the metal protective shell. The broadband freeform surface focusing micro-optical device has a reflective surface, which substantially overlaps the optical focusing area of ​​the OCT near-infrared beam and the FLIM excitation beam, and overlaps with the IVUS main acoustic beam imaging area or scanning section of the ultrasonic transducer module in the same axial position and circumferential direction. The flexible main body section is used to transmit rotational torque during rotational scanning, and the flexible main body section is connected to the front-end imaging section.

[0007] Furthermore, the reflective surface of the broadband freeform surface focusing micro-optical device is coated with a reflective film.

[0008] Furthermore, the reflective film is an aluminum-based reflective film, a silver-based reflective film, or a multilayer dielectric reflective film.

[0009] Furthermore, the flexible main body segment includes an optical fiber and an ultrasonic signal cable. The optical fiber is used to conduct OCT near-infrared beams and FLIM excitation beams. The other end of the optical fiber extends into the metal protective shell and is connected to the broadband freeform surface focusing micro-optical device. The fiber core of the optical fiber is aligned with the broadband freeform surface focusing micro-optical device. The ultrasonic signal cable extends into the metal protective shell and is connected to the ultrasonic transducer module.

[0010] Furthermore, the metal protective shell has a lateral acousto-optic window, which is used to allow the OCT near-infrared beam, the FLIM excitation beam, and the IVUS main acoustic beam to pass through.

[0011] Furthermore, the flexible main body segment also includes a torque spring, with the optical fiber and the ultrasonic signal cable located inside the torque spring, and the torque spring driving the optical fiber to rotate and scan.

[0012] Furthermore, the ultrasonic surface of the ultrasonic transducer module faces the reflective surface side of the broadband freeform surface focusing micro-optical device.

[0013] Furthermore, the optical fiber adopts one of the following structures: single-mode optical fiber, double-clad optical fiber, or multi-core optical fiber.

[0014] Furthermore, the geometric parameters of the reflecting surface include quadratic surface constants. Normalized radius aspherical coefficient and the tilt angle of the reflecting surface The position of a point on the reflecting surface relative to the reference plane is defined as the sag z, and its relationship with the lateral coordinate x and axial coordinate y can be determined by the following formula: .

[0015] Furthermore, the OCT near-infrared beam, the FLIM excitation beam, and the IVUS main acoustic beam are coaxially integrated.

[0016] The beneficial effects of this invention are: The trimodal coaxial integrated catheter structure for in vivo cavity imaging proposed in this invention utilizes broadband freeform surface focusing micro-optical devices to focus the OCT near-infrared beam and the FLIM excitation beam to the same point, which coincides with the imaging point of the ultrasound transducer module. This achieves high-resolution focusing of the FLIM excitation beam and the OCT near-infrared beam. Combined with the ultrasound transducer module, it can meet the requirements of trimodal imaging, ensuring native and accurate matching of multimodal images from the structural source. Attached Figure Description

[0017] Figure 1 This is a structural diagram of the trimodal coaxial integrated catheter structure for in vivo cavity imaging according to the present invention; Figure 2 This is a cross-sectional view of the front imaging working section of the trimodal coaxial integrated catheter structure for in vivo cavity imaging according to the present invention. Figure 3 This is a back-to-back arrangement illustration of the trimodal coaxial integrated catheter structure for in vivo cavity imaging according to the present invention; Figure 4 This is a structural diagram of a second embodiment of the trimodal coaxial integrated catheter structure for in vivo cavity imaging of the present invention; Figure 5 This is a schematic diagram showing the sequential arrangement of the trimodal coaxial integrated catheter structure for in vivo cavity imaging according to the present invention; In the figure: front-end imaging working section 1, ultrasonic transducer module 11, broadband freeform surface focusing micro-optical device 12, reflective film 121, flexible main body section 2, torque spring 21, ultrasonic signal cable 22, optical fiber 23; The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] To more clearly and completely illustrate the technical solution of the present invention, the present invention will be further described below with reference to the accompanying drawings.

[0019] Please refer to Figures 1-5 This invention proposes a trimodal coaxial integrated catheter structure for in vivo cavity imaging, comprising a flexible main body segment 2 and a front imaging working segment 1, wherein: The front-end imaging section 1 includes a metal protective shell and a broadband freeform surface focusing micro-optical device 12 and an ultrasonic transducer module 11 disposed inside the metal protective shell. The broadband freeform surface focusing micro-optical device 12 has a reflective surface, which substantially overlaps the optical focusing area of ​​the OCT near-infrared beam and the FLIM excitation beam, and overlaps with the IVUS main acoustic beam imaging area or scanning section of the ultrasonic transducer module in the same axial position and circumferential direction. The flexible main body section 2 is used to transmit the rotational torque 1 in the rotational scanning, and the flexible main body section 2 is connected to the front-end imaging section 1.

[0020] Specifically, an opening is provided on the metal protective shell, and the broadband freeform surface focusing micro-optical device 12 and the ultrasonic transducer module 11 are fixed inside the metal protective shell. The optical focusing areas of the OCT near-infrared beam and the FLIM excitation beam are basically coincident, and overlap with the IVUS main acoustic beam imaging area or scanning section of the ultrasonic transducer module 11 in the same axial position and circumferential direction, thereby achieving high-resolution focusing of the FLIM excitation beam and the OCT near-infrared beam. In conjunction with the ultrasonic transducer module 11, it can meet the requirements of three-modal imaging: IVUS ultrasonic imaging, OCT near-infrared optical coherence tomography, and FLIM fluorescence lifetime imaging, ensuring native and accurate matching of multimodal images from the structural root.

[0021] Furthermore, the reflective surface of the broadband freeform surface focusing micro-optical device 12 is coated with a reflective film 121.

[0022] Specifically, by controlling the surface shape of the broadband freeform surface focusing micro-optical device 12 and coating the reflective surface with a reflective film 121, high-resolution reflective focusing of both FLIM beams (e.g., 320-420nm ultraviolet light) and OCT beams (e.g., 800-1400nm infrared light) can be achieved simultaneously, reducing dual-band chromatic aberration and focus shift, and improving dual-mode focusing consistency.

[0023] Furthermore, the reflective film 121 is an aluminum-based reflective film 121, a silver-based reflective film 121, or a multilayer dielectric reflective film 121.

[0024] Specifically, the reflective film 121 can also be made of materials other than aluminum-based reflective film 121, silver-based reflective film 121, or multilayer dielectric reflective film 121, depending on the actual situation.

[0025] Furthermore, the flexible main body segment 2 includes an optical fiber 23 and an ultrasonic signal cable 22. The optical fiber 23 is used to conduct OCT near-infrared beams and FLIM excitation beams. The other end of the optical fiber 23 extends into the metal protective shell and is connected to the broadband freeform surface focusing micro-optical device 12. The fiber core of the optical fiber 23 is aligned with the broadband freeform surface focusing micro-optical device 12. The ultrasonic signal cable 22 extends into the metal protective shell and is connected to the ultrasonic transducer module 11.

[0026] Specifically, one end of the optical fiber 23 is connected to the OCT near-infrared beam and the FLIM excitation beam source, and the other end is connected to the broadband freeform surface focusing micro-optical device 12. The optical fiber 23 emits the OCT near-infrared beam and the FLIM excitation beam onto the broadband freeform surface focusing micro-optical device 12, and focuses them through the broadband freeform surface focusing micro-optical device 12. The ultrasonic signal cable 22 is directly connected to the ultrasonic transducer.

[0027] Furthermore, the metal protective shell has a lateral acousto-optic window, which is used to allow the OCT near-infrared beam, the FLIM excitation beam, and the IVUS main acoustic beam to pass through.

[0028] Specifically, the OCT near-infrared beam, the FLIM excitation beam, and the IVUS main acoustic beam are collinear after being reflected by the reflective surface of the broadband freeform focusing micro-optical device, and then pass through the lateral acousto-optic window to scan the target.

[0029] Furthermore, the flexible main body segment 2 also includes a torque spring 21, the optical fiber 23 and the ultrasonic signal cable 22 are located inside the torque spring 21, and the torque spring 21 drives the optical fiber to rotate and scan.

[0030] Specifically, the torque spring 21 is wrapped around the outside of the optical fiber 23 and the ultrasonic signal cable 22. While protecting the optical fiber 23 and the ultrasonic signal cable 22, it also provides some support for them. The torque spring 21 can adapt to high-speed rotating scanning conditions and ensure the stability of the beam trajectory.

[0031] Furthermore, the ultrasonic surface of the ultrasonic transducer module 11 faces the reflective surface of the broadband freeform surface focusing micro-optical device 12.

[0032] For details, please refer to Figure 3 , Figure 4 , Figure 5 The ultrasonic transducer module 11 and the broadband freeform surface focusing micro-optical device 12 have a back-to-back ( Figure 3 ), coplanar ( Figure 4 ),order( Figure 5 ) and collinear ( Figure 2There are four arrangement methods. Back-to-back arrangement has the worst registration accuracy because the imaging areas are completely separated. Coplanar arrangement has registration errors due to azimuth deviation. Sequential arrangement introduces motion and time errors because the axial distribution requires the position to be calculated based on the retraction speed. Collinear arrangement achieves complete overlap and synchronous acquisition of imaging areas through coaxiality, eliminating spatial offset and time difference interference. Therefore, it can obtain the most strictly accurate registered image. By installing the ultrasonic transducer at the same axial position of the ultraviolet and infrared light focal points, multiple different arrangement methods of three-modal imaging can be realized.

[0033] Furthermore, optical fiber 23 adopts one of the following structures: single-mode fiber, double-clad fiber, or multi-core fiber. Specifically, the type of fiber 23 can be selected according to the actual situation. For example, it can be a single-mode fiber, a double-clad fiber, or a multi-core fiber structure. It can also be combined with a free-space optical path. If a double-clad fiber is used as the optical carrier, the core layer of the fiber 23 is used to transmit infrared signals, while the cladding is used to transmit fluorescence excitation light and to transmit and collect the excitation fluorescence signal. This enables the multiplexing of dual optical modes (OCT near-infrared beam and FLIM excitation beam) in a single physical channel. At the same time, it can achieve high-resolution focusing of the OCT near-infrared beam and FLIM excitation beam in both bands and efficient FLIM fluorescence collection.

[0034] Furthermore, the geometric parameters of the reflecting surface include the quadratic surface constant. Normalized radius aspherical coefficient and the tilt angle of the reflecting surface The position of a point on the reflecting surface relative to the reference plane is defined as the sag z, and its relationship with the lateral coordinate x and axial coordinate y can be determined by the following formula:

[0035] Specifically, when the reflecting surface is a standard ellipsoid, the 23-core fiber is the first focus of the ellipsoid, and the focal point is the second focus of the ellipsoid. The focusing position can be adjusted by controlling the geometric parameters.

[0036] Furthermore, the OCT near-infrared beam, the FLIM excitation beam, and the IVUS main acoustic beam are coaxially integrated.

[0037] Specifically, the OCT near-infrared beam, FLIM excitation beam, and IVUS main acoustic beam are coaxially integrated, allowing for the acquisition of comprehensive complementary diagnostic information in a single intervention, thus meeting the requirements for intervention in stenotic cavities.

[0038] Of course, the present invention may have many other embodiments. Based on this embodiment, other embodiments obtained by those skilled in the art without any creative effort are all within the scope of protection of the present invention.

Claims

1. A trimodal coaxial integrated catheter structure for in vivo cavity imaging, characterized in that, It includes a flexible main body section and a front-end imaging working section, wherein: The front-end imaging section includes a metal protective shell and a broadband freeform surface focusing micro-optical device and an ultrasonic transducer module disposed inside the metal protective shell. The broadband freeform surface focusing micro-optical device has a reflective surface, which substantially overlaps the optical focusing area of ​​the OCT near-infrared beam and the FLIM excitation beam, and overlaps with the IVUS main acoustic beam imaging area or scanning section of the ultrasonic transducer module in the same axial position and circumferential direction. The flexible main body section is used to transmit rotational torque during rotational scanning, and the flexible main body section is connected to the front-end imaging section.

2. The trimodal coaxial integrated catheter structure for in vivo cavity imaging according to claim 1, characterized in that, The reflective surface of the broadband freeform surface focusing micro-optical device is coated with a reflective film.

3. The trimodal coaxial integrated catheter structure for in vivo cavity imaging according to claim 2, characterized in that, The reflective film is an aluminum-based reflective film, a silver-based reflective film, or a multilayer dielectric reflective film.

4. The trimodal coaxial integrated catheter structure for in vivo cavity imaging according to claim 1, characterized in that, The flexible main body section includes optical fibers and ultrasonic signal cables. The optical fibers are used to conduct OCT near-infrared beams and FLIM excitation beams. The other end of the optical fibers extends into the metal protective shell and is connected to the broadband freeform surface focusing micro-optical device. The fiber core of the optical fibers is aligned with the broadband freeform surface focusing micro-optical device. The ultrasonic signal cables extend into the metal protective shell and are connected to the ultrasonic transducer module.

5. The trimodal coaxial integrated catheter structure for in vivo cavity imaging according to claim 1, characterized in that, The metal protective shell has a lateral acousto-optic window, which is used to allow the OCT near-infrared beam, the FLIM excitation beam, and the IVUS main acoustic beam to pass through.

6. The trimodal coaxial integrated catheter structure for in vivo cavity imaging according to claim 4, characterized in that, The flexible main body section also includes a torque spring, and the optical fiber and the ultrasonic signal cable are located inside the torque spring. The torque spring drives the optical fiber to rotate and scan.

7. The trimodal coaxial integrated catheter structure for in vivo cavity imaging according to claim 1, characterized in that, The ultrasonic surface of the ultrasonic transducer module faces the reflective surface of the broadband freeform surface focusing micro-optical device.

8. The trimodal coaxial integrated catheter structure for in vivo cavity imaging according to claim 4, characterized in that, The optical fiber adopts one of the following structures: single-mode fiber, double-clad fiber, or multi-core fiber.

9. The trimodal coaxial integrated catheter structure for in vivo cavity imaging according to claim 1, characterized in that, The geometric parameters of the reflecting surface include the quadratic surface constant. Normalized radius aspherical coefficient and the tilt angle of the reflecting surface The position of a point on the reflecting surface relative to the reference plane is defined as the sag z, and its relationship with the lateral coordinate x and axial coordinate y can be determined by the following formula: 。 10. The trimodal coaxial integrated catheter structure for in vivo cavity imaging according to claim 1, characterized in that, The OCT near-infrared beam, the FLIM excitation beam, and the IVUS main acoustic beam are coaxially integrated.

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